U.S. Pat. No. 4,851,601—applied for protection on 19 Jan. 1988, description defines a method of getting hydrocarbon oils from waste plastics which is based on thermal cracking in liquid phase and through catalytic conversion of vapors of cracking products with catalyst presence.
From Japanese Patent, applied for protection on 19 Aug. 1996, published as EP 0763412, there is known a waste plastics pyrolysis reactor which involves a reactor with a waste plastics inlet located at one end and a liquefied plastic outlet and hydrogen chloride outlet located at the next end, and a waste heater situated between the plastic inlet and hydrogen chloride outlet. The reactor has a screw funnel heater for conducting plastics in the reactor from charge to outlet.
From U.S. Pat. No. 6,066,263, applied for protection on 12 Mar. 1998, there is known a system for hydrothermal reaction conversion of waste plastics into oil. Plant has a tank for keeping a mixture of water and plastics, a high-pressure pump connected through a flow channel, and a shift valve with tank. The shift valve is connected with a water passing channel. The reactor has bowed pipes connected with an injection pump. The bowed pipes are equipped with heating agents and are connected through a pressure reduction valve with effluent tank. The velocity of flow of the reaction mixture passed to the reactor may be controlled by the pressure reduction valve. Thermal degradation of the mixture is reached in the reactor device under pressure and temperature conditions equal to, or above, a value by which a supercritical condition of water is achieved, and under the turbulent flow conditions generated partly by the curved piping.
U.S. Pat. No. 6,534,689, applied for protection on 24 Aug. 2001, description defines a method of pyrolysis of waste plastics leading to fuel production. In order to separate solid particles from liquids the cyclone uses high vehicle velocity and high inert gas temperature as heat transfer carriers. This invention utilizes inert gas and hydrocarbon vapors as a heating medium.
From patent description WO 2005/065006, with priority on 23 Dec. 2003, a reactor for enrichment of recoverable oil from waste plastics is known. The invention is a reactor with FIR heater therein that coverts waste plastics into oil. The FIR heater consists of electrical resistance space, a far infrared radiator, an insulator, a protective shell, a tight set and other parts. The far infrared ray radiator can be rod-shaped, band-shaped and can be made into other shapes, and on the outside is encased by metal pipe, and painted with the far infrared radiator. So the infrared ray can directly heat the plastics, thereby turning the waste plastics into oil. This technique of splitting oil dregs and emulsification will scatter the oil dregs into atoms below 100 μm, and combine them in the emulsified oil equitably, and get 30-60° C. liquid oil in the emulsification container. Hot oil will be directly changed into burnable liquid oil and it can be stored safely at normal temperatures.
From US Patent Application Publication No US2005/0075521, applied for protection on 20 Jan. 2003, a method and plant for conversion of plastics into oil with presence of inert gas is known. The plastic raw material is dissolved in a dissolution section to form an expanded plastic and sent to an inclined first-stage decomposition column and a second-stage decomposition column. The second-stage decomposition column is adjacent to the first-stage decomposition column. Both columns have fixed temperature distributions. The plastic is depolymerized and decomposed into a light secondarily decomposed gas. The extracted secondarily decomposed gas is cooled into oil in condensers and collected in oil storage tanks.
From Polish Patent No P 380619, applied for protection on 16 Sep. 2006, the method and apparatus for catalytic depolymerization of polyolefinic waste plastics characterized by two reactors in which depolymerization takes place, one tank reactor and second flow reactor operating in cooperation is known. Shredded plastic waste is first heated, melted, and pumped under the reaction medium surface. Later plastic molten mass is dispersed in the reaction medium. The depolymerization process occurs in presence of the catalyst. From the reactor bottom reacting mixture is pumped to the flow reactor in which it is heated up to 400° C. The reaction occurs under normal and negative pressure. Pressure in the reactor depends on the planned outcome product properties. Inside flow reactor depolymerization takes place. Gas and liquid mixture comes into the tank reactor where it is split into gas and liquid fraction. Liquid phase is heated up and melts incoming plastic feedstock. In the bottom reactor area, in 360° C., the initial reaction takes place.
In the upper section, in around 400° C., the split into gas and liquids takes place. The hydrocarbon vapors produced come through the active chemically neutralizing filter and condense. Process is continuous.
From Polish Patent Application P-383709, applied for protection on 7 Nov. 2007, the apparatus and method for depolymerization of waste plastics, especially polyolefins, with removing reaction leftovers and residues is known. The apparatus consists of a feeding conveyor, a pyrolysis reactor, a and discharging section and is characterized by a gas engaging stabilizer equipped with a mixer and working in a close loop at least one external pyrolysis reactor with screw or ribbon mixer and a pipe that closes the loop. The depolymerization process is carried out with inert gas presence and characterized by reactor enforced dual flow in which one mixing direction is used as well to discharge the reaction residue.
From Polish patent application No P-386410, applied for protection on 31 Oct. 2008, an apparatus for thermolysis of waste plastics, especially polyolefins, and a method of thermolysis with continuous feeding and continuous discharging carbonizable substances and reaction leftovers is known. The apparatus includes a plastic feeding system, a pyrolysis reactor, a discharge system and according to the invention is characterized in that after the plastic feeding system is situated, the extruder and pyrolysis reactor, which height is at least 1.5 times bigger than its diameter, are connected. The pyrolysis reactor is equipped with a dual high speed propeller. The method for thermolysis of plastic waste, especially polyolefins, with presence of inert gas, according to the claims is characterized in that plastic waste is continuously fed to the extruder where it is plasticized from 180° C. up to the temperature of the reactor later, is fed to the pyrolysis reactor, where at 350-450° C. at agitator's 30-1500 rpm, the thermolysis is carried out with continuous two step fractional condensation where a light product boiling below 180° C. goes to a storage tank with a cold jacket and a heavy product boiling above 180° C. is conducted to a hot jacket tank.